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Two-dimensional grating line parameter calibration based on biaxial phase mapping 认领 引用
1
作者 TENG Hai-rui LIANG Xu +3 位作者 JIN Si-yu SUN Yu-jia LI Wen-hao LIU Zhao-wu 《中国光学（中英文）》 EI CAS CSCD 北大核心 2026年第2期407-420,共14页
The two-dimensional grating serves as a critical component in plane grating interferometers for achieving high-precision multidimensional displacement measurements.The calibration of grating groove density and orthogo... The two-dimensional grating serves as a critical component in plane grating interferometers for achieving high-precision multidimensional displacement measurements.The calibration of grating groove density and orthogonality error of grating grooves not only improves the positioning accuracy of grating interferometers but also provides essential feedback for optimizing two-dimensional grating fabrication.This study proposes a method for simultaneous calibration of these parameters using orthogonal heterodyne laser interferometry.A two-dimensional grating interferometer is built with the grating to be measured,and a biaxial laser interferometer provides a displacement reference for it.The phase mapping relationship between grating interference and laser interference is established.The interference phase information obtained by any two displacements can simultaneously solve the above three parameters and obtain the grating installation error.The feasibility of the proposed method is verified by using a 1200 gr/mm two-dimensional grating.The standard deviation of the grating groove density in the X and Y directions is 0.012 gr/mm and 0.014 gr/mm,respectively.The standard deviation of the orthogonality error of grating grooves is 0.004°,and the standard deviation of the installation error is 0.002°.Compared with the atomic force microscope method,the consistency of the grating groove density in the X and Y directions is better than 0.03 gr/mm and 0.06 gr/mm,and the orthogonality error of grating grooves is better than 0.008°.The experimental results show that the proposed method can be simply and efficiently applied to the calibration of the grating line parameters of the two-dimensional grating. 展开更多
关键词 two-dimensional grating grating line parameter calibration grating groove density orthogonality error of grating grooves
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Study on Physical Mechanism of Dual-source Dual-energy CT Multi-parameter Imaging and Parameter Calibration of Region of Interest in Pulmonary Nodules 认领 引用
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作者 LIN Rong LAI Fa-ming HUANG Mei-hua 《Chinese Journal of Biomedical Engineering(English Edition)》 CAS 2026年第1期26-33,共8页
Objective:This study aims to explore the physical mechanism underlying dual-source dual-energy CT multi-parameter imaging,establish a standardized calibration workflow for core region of interest(ROI)parameters of pul... Objective:This study aims to explore the physical mechanism underlying dual-source dual-energy CT multi-parameter imaging,establish a standardized calibration workflow for core region of interest(ROI)parameters of pulmonary nodules,including iodine concentration(IC)and effective atomic number(Zeff),and validate the calibration accuracy and clinical diagnostic efficacy for the qualitative differentiation of benign and malignant pulmonary nodules.Methods:According to the hardware characteristics of dual-source CT(80 kVp/140 kVp and100 k Vp/Sn140 kVp dual-energy scanning protocols)and the linear basis material decomposition algorithm,the computational formulas for IC and Zeff were systematically derived.The entire dual-energy CT scanning procedure was digitally reproduced via GATE-based Monte Carlo simulation,and the independent and combined effects of spectral overlap and scattering artifacts on quantitative imaging parameters were quantitatively analyzed.A total of 78 patients with pulmonary nodules(39 benign and39 malignant cases)and 20 healthy volunteers were enrolled in this study.All participants underwent contrast-enhanced dual-energy CT scanning.A combined manual and semi-automatic strategy was adopted for pulmonary nodule ROI delineation to acquire the mean values and variation coefficients of IC and Zeff.With postoperative or biopsy pathological results as the gold standard,the differences in dual-energy quantitative parameters between benign and malignant nodules were compared.Targeting the primary error sources including spectral distortion and ROI delineation deviation,a Monte Carlo-based parameter calibration algorithm was constructed to optimize the weighting coefficients of basis material decomposition and refine the threshold of ROI segmentation.Results:The quantitative accuracy of dualenergy CT-derived IC and Zeff was predominantly compromised by spectral overlap and scattering artifacts.Spectral overlap contributed to approximately 40%of total IC measurement errors and 35%of total Zeff errors,while scattering artifacts accounted for 30%of errors for both parameters.The proposed calibration algorithm reduced the IC measurement error from 8.2%to 2.9%and the Zeff measurement error from5.1%to 1.8%.After calibration,malignant pulmonary nodules presented significantly higher IC values[(4.2±1.1)mg/mL]and lower Zeff values(7.8±0.3)than benign nodules[(2.1±0.6)mg/mL,8.5±0.4,P<0.001].Conclusion:Spectral overlap and scattering artifacts are the dominant systematic and random errors affecting the quantitative reliability of dual-source dual-energy CT multi-parameter imaging.The GATE Monte Carlo-based calibration algorithm can substantially improve the measurement accuracy and repeatability of pulmonary nodule ROI parameters,providing a standardized technical reference for clinical quantitative imaging and qualitative diagnosis of pulmonary nodules. 展开更多
关键词 dual-source dual-energy CT multi-parameter imaging physical mechanism pulmonary nodule region of interest parameter calibration
Calibration and uniqueness analysis of microparameters for DEM cohesive granular material 认领 引用 被引量：8
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作者 Songtao Ji Jurij Karlovšek 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2022年第1期121-136,共16页
The differential evolution(DE)algorithm was deployed to calibrate microparameters of the DEM cohesive granular material.4 macroparameters,namely,uniaxial compressive strength,direct tensile strength,Young’s modulus a... The differential evolution(DE)algorithm was deployed to calibrate microparameters of the DEM cohesive granular material.4 macroparameters,namely,uniaxial compressive strength,direct tensile strength,Young’s modulus and Poisson’s ratio,can be calibrated to high accuracy.The best calibration accuracy could reach the sum of relative errors REsum<0.1%.Most calibrations can be achieved with REsum<5%within hours or REsum<1%within 2 days.Based on the calibrated results,microparameters uniqueness analysis was carried out to reveal the correlation between microparameters and the macroscopic mechanical behaviour of material:(1)microparameters effective modulus,tensile strength and normal-to-shear stiffness ratio control the elastic behaviour and stable crack growth,(2)microparameters cohesion and friction angles present a negative linear correlation that controls the axial strain and lateral strain prior to the peak stress,and(3)microparameters friction coefficient controls shear crack friction and slip mainly refers to the unstable crack behaviour.Consideration of more macroparameters to regulate the material mechanical behaviour that is dominated by shear crack and slip motion is highlighted for future study.The DE calibration method is expected to serve as an alternative method to calibrate the DEM cohesive granular material to its peak strength. 展开更多
关键词 Discrete element method(DEM) Particle flow code(PFC) Differential evolution(DE) Parameter calibration Uniqueness analysis Post-peak behaviour
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Calibration of Discrete Element Heat Transfer Parameters by Central Composite Design 认领 引用 被引量：1
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作者 Zongquan DENG Jinsheng CUI +1 位作者 Xuyan HOU Shengyuan JIANG 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第2期419-427,共9页
The efficiency and precision of parameter calibration in discrete element method （DEM） are not satisfactory, and parameter calibration for granular heat transfer is rarely involved. Accordingly, parameter calibratio... The efficiency and precision of parameter calibration in discrete element method （DEM） are not satisfactory, and parameter calibration for granular heat transfer is rarely involved. Accordingly, parameter calibration for granular heat transfer with the DEM is studied. The heat transfer in granular assemblies is simulated with DEM, and the effective thermal conductivity （ETC） of these granular assemblies is measured with the transient method in simulations. The measurement testbed is designed to test the ETC of the granular assemblies under normal pressure and a vacuum based on the steady method. Central composite design （CCD） is used to simulate the impact of the DEM parameters on the ETC of granular assemblies, and the heat transfer parameters are calibrated and compared with experimental data. The results show that, within the scope of the considered parameters, the ETC of the granular assemblies increases with an increasing particle thermal conductivity and decreases with an increasing particle shear modulus and particle diameter. The particle thermal conductivity has the greatest impact on the ETC of granular assemblies followed by the particle shear modulus and then the particle diameter. The calibration results show good agreement with the experimental results. The error is less than 4%, which is within a reasonable range for the scope of the CCD parameters. The proposed research provides high efficiency and high accuracy parameter calibration for granular heat transfer in DEM. 展开更多
关键词 Granular assembly · Parameter calibration · Effective thermal conductivity （ETC） · Discrete element method （DEM） · Central composite design （CCD） · Vacuum
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STRUCTURAL PARAMETERS CALIBRATION BY POSTURE MEASUREMENT ON PARALLEL 6-DOF PLATFORM 认领 引用 被引量：1
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作者 Wu Jiangning Li ShilunState Key Laboratory of Fluid Power Transmission and Control, Zhejiang University,Hangzhou 310027, China 《Chinese Journal of Mechanical Engineering》 EI CAS 2002年第4期334-338,343,共5页
Some approaches to measure parallel 6-degree of freedom platform's posturestatically and to calibrate the platform's actual structural parameters by measuring a series of theplatform's varying postures are... Some approaches to measure parallel 6-degree of freedom platform's posturestatically and to calibrate the platform's actual structural parameters by measuring a series of theplatform's varying postures are studied. In the case where high posture accuracy is requiredrelatively, to obtain the platform's actual structural parameters is very important. Threedimensions measurement with 2 theodolites are used to obtain the platform's postures statically andNewton iterative method is adopted to calibrate structural parameters. Some measures taken in themeasurement and the calibration are discussed in detail. And the experiment results of theplatform's posture control before and after the calibration are given. The results show that theplatform's posture control accuracy after the calibration is improved notably. 展开更多
关键词 parallel 6-DOF platform theodolite posture measurement nonlinearequation group structural parameters calibration
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An Integrated Experimental-Simulation Calibration Method for the Constitutive Model of 6005A-T6 Aluminum Alloy Welds 认领 引用
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作者 Yu Zhu Lele Zhang +1 位作者 Weiyuan Dou Wen Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2025年第1期233-245,共13页
Due to the different microstructures caused by the heat source effect,welding joints exhibit significant differences in mechanical properties compared to the base material.Precise characterization of the constitutive ... Due to the different microstructures caused by the heat source effect,welding joints exhibit significant differences in mechanical properties compared to the base material.Precise characterization of the constitutive characteristics of the welded joint requires a large number of repetitive experiments,which are costly,inefficient,and have limited accuracy improvements.This paper proposes an integrated experimental-simulation-based inverse calibration method,which establishes a calibration optimization problem based on the corresponding constitutive model and a finite element calculation model built by the distribution of hardness in the weldment.Using the global tensile force-displacement curve of the MIG-welded 6005A-T6 aluminum alloy specimen and the experimental data of local deformation with time change obtained from DIC(Digital Image Correlation),the parameters involved in the constitutive models are optimized accordingly.This method can directly obtain the constitutive characteristics of the weldment under conditions of limited experiments and insufficient data.Additionally,the adaptability of the constitutive model to the calibration method and the influence of optimization results are discussed and analyzed.The results indicate that the global force-displacement response of the non-saturated Ramberg-Osgood(R-O)model is in the best agreement with that of the experimental data,and the energy error is only 2.62%,followed by the MPL model,while the saturation-based Voce model shows the largest simulation error in terms of the presented object.Furthermore,the simulation results of R-O,Voce,and MPL models in the local area are far superior to traditional fitting methods. 展开更多
关键词 6005A-T6 aluminum alloy MIG-weld joint Parameter calibration Elastic-plastic constitutive model DIC
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Calibration of Elastic-Plastic Degradation Model for 40Cr Steel Applied in Finite Element Simulation of Shear Pins of Friction Pendulum Bearings 认领 引用
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作者 Mianyue Yang Huasheng Sun Weigao Sheng 《Computers, Materials & Continua》 SCIE EI 2025年第11期2749-2761,共13页
The shear pin of the friction pendulum bearing(FPB)can be made of 40Cr steel.In conceptual design,the optimal cut-off point of the shear pin is predetermined,guiding the design of bridges isolated by FPBs to maximize ... The shear pin of the friction pendulum bearing(FPB)can be made of 40Cr steel.In conceptual design,the optimal cut-off point of the shear pin is predetermined,guiding the design of bridges isolated by FPBs to maximize their isolation performance.Current researches on the shear pins are mainly based on linear elastic models,neglecting their plasticity,damage,and fracture mechanical properties.To accurately predict its cutoff behavior,the elastic-plastic degradationmodel of 40Cr steel is indeed calibrated.For this purpose,the Ramberg-Osgoodmodel,the Bao-Wierzbicki damage initiation criterion,and the linear damage evolution criterion were selected to develop the elastic-plastic degradation model of 40Cr.Subsequently,parameter calibration of this model was performed through uniaxial tensile tests on two sets of six smooth,round bars with different diameters.Following this,finite element simulations were conducted for the pure shear test of grade 10.9 high-strength bolts made of 40Cr steel,aiming to verify the elasticplastic degradation model.The results showed that the failure modes and force-displacement curves simulated by the finite element method were in good agreement with the test results.Moreover,the error between the primary characteristic parameters(initial stiffness,peak load,fracture displacement,and absorbed energy)obtained by finite element calculation and the test values was within 15%.These results demonstrated that the calibration elastic-plastic degradation model of 40Cr steel can predict the cutoff of the shear pin. 展开更多
关键词 Friction pendulum bearing shear pin 40Cr steel elastic-plastic degradationmodel uniaxial tensile test parameters calibration
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Calibration of rototilled soil block discrete element parameters after rotary tillage in rape planting by machinery 认领 引用
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作者 Fanggang Shi Mingliang Wu +3 位作者 Zhihao Zhao Haiyang Chen Xiaohu Jiang Wei Quan 《International Journal of Agricultural and Biological Engineering》 SCIE 2026年第2期28-38,共11页
This study sought to construct and empirically validate a discrete element method(DEM)particle model representing post-tillage soil blocks.This model was developed to facilitate a detailed examination of granular move... This study sought to construct and empirically validate a discrete element method(DEM)particle model representing post-tillage soil blocks.This model was developed to facilitate a detailed examination of granular movement and contact mechanics during the shaping process of planting chambers for rape plants.The research specifically targeted the sticky,cohesive soil prevalent in rice paddy fields of the middle and lower Yangtze River region.Simulations were conducted using EDEM software to improve the accuracy with which soil-tool interactions are predicted for the design and optimization of mechanical transplanters.The physical and bonding parameters of the sticky soil were calibrated using the Hertz-Mindlin with Johnson-Kendall-Roberts(JKR)contact model and Hertz-Mindlin with Bonding contact model.A particle replacement method was adopted to create a discrete element model of cohesive soil aggregates with different shapes and sizes after rotary tillage.The accumulation angle of soil aggregates was used as the evaluation index in both the simulation and physical experiments.Design-Expert software was used to design a four-factor,three-level simulation experiment to identify the optimal parameter combinations for the physical and mechanical properties of the sticky soil and the JKR contact model,which comprised a soil-soil static friction coefficient of 0.32,soil-soil rolling friction coefficient of 0.10,soil-steel static friction coefficient of 0.51,and surface energy of soil for the JKR model of 5.50 J/m2.Next,the steepest climbing test and Box-Behnken orthogonal combination test were then used to narrow down the range of values for the significant factors and identify the optimal parameter combinations for the bonding contact model parameters,which included a bonding bond normal contact stiffness of 2.1×106N/m,a bonding bond tangential contact stiffness of 2.2×106N/m,a normal ultimate stress of 0.55 MPa,a tangential ultimate stress of 0.55 MPa,and a bonding radius of 12 mm.Field experiments were conducted using a flat box device to measure the soil evenness and firmness after ridge formation and compaction by a rotary tiller.The results of these experiments were compared with the discrete element simulation optimization results.The relative errors between the field test results and the simulation test results for soil flatness and compaction were 10.7%and 9.8%,respectively,which indicated good accuracy of the parameters calibrated and optimized by EDEM discrete element simulation software.Overall,this research can provide a reference for understanding the working mechanism and optimizing the parameters of soil touching components in rape transplanting equipment. 展开更多
关键词 rape soil block soil firmness discrete element method parameter calibration
Calibration of parameters for a discrete element model of cotton field residual film-soil mixtures 认领 引用
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作者 Jinming Li Jiaxi Zhang +3 位作者 Yichao Wang Zebin Gao Xiaoxuan Wang Shilong Shen 《International Journal of Agricultural and Biological Engineering》 SCIE 2026年第1期59-66,共8页
During residual film recovery operations,the mixing of residual film with soil and the absence of accurate interaction parameters significantly hinder the optimization of key machinery components.To tackle this issue,... During residual film recovery operations,the mixing of residual film with soil and the absence of accurate interaction parameters significantly hinder the optimization of key machinery components.To tackle this issue,this study develops a discrete element simulation model based on the Hertz-Mindlin with JKR(Johnson-Kendall-Roberts)contact model,using the residual film-soil mixture as the simulated material.The contact parameters were calibrated through a combination of physical experiments and EDEM simulations.Using Design-Expert software,angle of repose tests and Plackett-Burman experiments were carried out to identify the parameters that have a significant influence on the angle of repose.The optimal set of parameters was determined through steepest ascent and Box-Behnken design(BBD)experiments:residual film-soil rolling friction coefficient 0.61,soil-soil rolling friction coefficient 0.60,soil-steel static friction coefficient 0.68,and soil JKR surface energy 0.46 J/m2.Validation results indicate relative errors of 4.58%for the angle of repose and 2.58%for the uniaxial compressive strength between simulated and measured values.These outcomes offer a useful reference for optimizing residual film recovery equipment and for modeling soil-residual film composite materials. 展开更多
关键词 cotton fields residual film-soil mixture parameter calibration angle of repose discrete element method uniaxial compression test
Calibration of DEM parameters for coated sunflower seeds based on dynamic stacking angle 认领 引用
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作者 Changji Liu Wuyun Zhao +4 位作者 Bin Feng Linrong Shi Bugong Sun Fei Dai Hui Li 《International Journal of Agricultural and Biological Engineering》 SCIE 2026年第1期283-294,共12页
To address the errors associated with the application of existing Discrete Element Method simulation parameters in roller-type precision seeders,this study focused on calibrating the key contact parameters of the‘Xin... To address the errors associated with the application of existing Discrete Element Method simulation parameters in roller-type precision seeders,this study focused on calibrating the key contact parameters of the‘Xinhe No.1’coated confectionary sunflower seeds,so as to provide a reliable simulation foundation for the optimization of the seeders.Through dynamic stacking angle experiments and comparative trials involving confectionary sunflowers(including Xinhe No.1)and oil sunflowers with significantly different physical properties,the optimal working conditions for the rotating drum were determined as a rotation speed of 10 r/min,304 Stainless Steel as the inner wall material,and a filling ratio of 30%.The study also clarified the variation patterns of the dynamic stacking angle.Physical experiments were conducted to measure the static friction coefficients,restitution coefficients,and inter-seed restitution coefficients between Xinhe No.1 seeds and three materials:304 Stainless Steel,Q235 Steel,and ABS Plastic.The physical dynamic stacking angle was obtained via a rotating drum experiment.A single-factor experiment was used to determine the range of simulation parameters,and a second-order orthogonal experiment was conducted using Design-Expert software to optimize contact parameters with the physical dynamic stacking angle as the target.The parameters were subsequently validated using the Discrete Element Method(DEM)simulation software EDEM 2022.3,hereinafter abbreviated as EDEM simulations.Finally,rolling friction coefficients between seeds and Q235 Steel and ABS Plastic were obtained through both simulation and physical experiments using alternative contact materials.The results showed that the static friction coefficients between Xinhe No.1 and 304 Stainless Steel,Q235 Steel,and ABS Plastic were 0.32,0.36,and 0.25,respectively;the restitution coefficients were 0.42,0.39,and 0.32;and the rolling friction coefficients were 0.012,0.011,and 0.010.The measured values of the inter-seed static friction coefficient,restitution coefficient,and rolling friction coefficient were 0.31,0.43,and 0.010,respectively.The relative error between simulated and physical stacking angles was<1.5%.Calibrated DEM parameters for Xinhe No.1 coated sunflower seeds provide a theoretical basis for optimizing the design of sunflower precision seeders. 展开更多
关键词 sunflower seed DEM parameter calibration dynamic stacking angle hill-drop planter
On the calibration and verification of Voronoi-based discontinuous deformation analysis for modeling rock fracture 认领 引用 被引量：7
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作者 Kaiyu Zhang Feng Liu +3 位作者 Kaiwen Xia Ying Xu Peng Dong Changyi Yu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第8期2025-2038,共14页
Since its introduction,discontinuous deformation analysis(DDA)has been widely used in different areas of rock mechanics.By dividing large blocks into subblocks and introducing artificial joints,DDA can be applied to r... Since its introduction,discontinuous deformation analysis(DDA)has been widely used in different areas of rock mechanics.By dividing large blocks into subblocks and introducing artificial joints,DDA can be applied to rock fracture simulation.However,parameter calibration,a fundamental issue in discontinuum methods,has not received enough attention in DDA.In this study,the parameter calibration of DDA for intact rock is carefully studied.To this end,a subblock DDA with Voronoi tessellation is presented first.Then,a modified contact constitutive law is introduced,in which the tensile and shear meso-strengths are modified to be independent of the bond lengths.This improvement can prevent the unjustified preferential failure of short edges.A method for imposing confining pressure is also introduced.Thereafter,sensitivity analysis is performed to investigate the influence of the calculated parameters and meso-parameters on the mechanical properties of modeled rock.Based on the sensitivity analysis,a unified calibration procedure is suggested for both cases with and without confining pressure.Finally,the calibration procedure is applied to two examples,including a biaxial compression test.The results show that the proposed Voronoi-based DDA can simulate rock fracture with and without confining pressure very well after careful parameter calibration. 展开更多
关键词 Discontinuous deformation analysis(DDA) Voronoi tessellation Parameter calibration Confining pressure Rock fracture
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Parameter Calibration of SWMM Model Based on Optimization Algorithm 认领 引用 被引量：2
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作者 Fengchang Xue Juan Tian +2 位作者 Wei Wang Yanran Zhang Gohar Ali 《Computers, Materials & Continua》 SCIE EI 2020年第12期2189-2199,共11页
For the challenge of parameter calibration in the process of SWMM(storm water management model)model application,we use particle Swarm Optimization(PSO)and Sequence Quadratic Programming(SQP)in combination to calibrat... For the challenge of parameter calibration in the process of SWMM(storm water management model)model application,we use particle Swarm Optimization(PSO)and Sequence Quadratic Programming(SQP)in combination to calibrate the parameters and get the optimal parameter combination in this research.Then,we compare and analyze the simulation result with the other two respectively using initial parameters and parameters obtained by PSO algorithm calibration alone.The result shows that the calibration result of PSO-SQP combined algorithm has the highest accuracy and shows highly consistent with the actual situation,which provides a scientific and effective new idea for parameter calibration of SWMM model,moreover,has practical guidance for flood control and disaster mitigation. 展开更多
关键词 SWMM parameter calibration PSO SQP
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Friction Coefficient Calibration of Sunflower Seeds for Discrete Element Modeling Simulation 认领 引用 被引量：2
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作者 Shuai Wang Zhihong Yu +2 位作者 Wenjie Zhang Dongxu Zhao Aorigele 《Phyton-International Journal of Experimental Botany》 SCIE 2022年第11期2559-2582,共24页
Sunflower(Helianthus annuus L.)is one of the four major oil crops in the world and has high economic value.However,the lack of discrete element method(DEM)models and parameters for sunflower seeds hinders the applicat... Sunflower(Helianthus annuus L.)is one of the four major oil crops in the world and has high economic value.However,the lack of discrete element method(DEM)models and parameters for sunflower seeds hinders the application of DEM for computer simulation in the key working processes of sunflower seed sowing and harvesting.The present study was conducted on two varieties of sunflower,and the DEM model of sunflower seeds was established by using 3D scanning technology based on the distribution of triaxial dimensions and volumes of the geometric model of sunflower seeds.Similarly,the physical characteristics parameters of sunflower seeds were determined by physical tests and the simulation parameters were screened for significance based on the Plackett-Burman test.Our results show that the coefficient of static friction between sunflower seeds and the coefficient of rolling friction have significant effects on the repose angle of the simulation test.Furthermore,the optimal range of the significance parameters was further determined by the steepest climb test,and the second-order regression model of the significance parameters and the repose angle was obtained according to the Box-Behnken design test and Response Surface Methodology(RSM),with the repose angle measured by the physical test as the optimized target value to obtain the optimal parameter combination.Finally,a two-sample t-test for the repose angle of the physical test and the repose angle of the simulation test yielded P>0.05.Our results confirms that the repose angle obtained from simulation is not significantly different from the physical test value,and the relative errors between the repose angle of the simulation test and the physical test are 1.43%and 0.40%,respectively,for the optimal combination of parameters.Based on these results it can be concluded that the optimal parameters obtained from the calibration can be used for DEM simulation experiments related to the sunflower seed sowing and harvesting process. 展开更多
关键词 Sunflower seeds repose angle response surface methodology simulation model DEM parameter calibration
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Parameter calibration of the tensile-shear interactive damage constitutive model for sandstone failure 认领 引用 被引量：1
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作者 Yun Shu Zheming Zhu +4 位作者 Meng Wang Weiting Gao Fei Wang Duanying Wan Yuntao Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1153-1174,共22页
The tensile-shear interactive damage(TSID)model is a novel and powerful constitutive model for rock-like materials.This study proposes a methodology to calibrate the TSID model parameters to simulate sandstone.The bas... The tensile-shear interactive damage(TSID)model is a novel and powerful constitutive model for rock-like materials.This study proposes a methodology to calibrate the TSID model parameters to simulate sandstone.The basic parameters of sandstone are determined through a series of static and dynamic tests,including uniaxial compression,Brazilian disc,triaxial compression under varying confining pressures,hydrostatic compression,and dynamic compression and tensile tests with a split Hopkinson pressure bar.Based on the sandstone test results from this study and previous research,a step-by-step procedure for parameter calibration is outlined,which accounts for the categories of the strength surface,equation of state(EOS),strain rate effect,and damage.The calibrated parameters are verified through numerical tests that correspond to the experimental loading conditions.Consistency between numerical results and experimental data indicates the precision and reliability of the calibrated parameters.The methodology presented in this study is scientifically sound,straightforward,and essential for improving the TSID model.Furthermore,it has the potential to contribute to other rock constitutive models,particularly new user-defined models. 展开更多
关键词 Damage constitutive model Parameter calibration Rock modeling Sandstone Dynamic impact load Tensile-shear interactive damage(TSID)model
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Identification of ductile fracture model parameters for three ASTM structural steels using particle swarm optimization 认领 引用
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作者 Ya-zhi ZHU Shi-ping HUANG Hao HONG 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2022年第6期421-442,共22页
Accurate prediction of ductile fracture requires determining the material properties,including the parameters of the constitutive and ductile fracture model,which represent the true material response.Conventional cali... Accurate prediction of ductile fracture requires determining the material properties,including the parameters of the constitutive and ductile fracture model,which represent the true material response.Conventional calibration of material parameters often relies on a trial-and-error approach,in which the parameters are manually adjusted until the corresponding finite element model results in a response matching the experimental global response.The parameter estimates are often subjective.To address this issue,in this paper we treat the identification of material parameters as an optimization problem and introduce the particle swarm optimization(PSO)algorithm as the optimization approach.We provide material parameters of two uncoupled ductile fracture models—the Rice and Tracey void growth model(RT-VGM)and the micro-mechanical void growth model(MM-VGM),and a coupled model—the gurson-Tvergaard-Needleman(GTN)model for ASTM A36,A572 Gr.50,and A992 structural steels using an automated PSO method.By minimizing the difference between the experimental results and finite element simulations of the load-displacement curves for a set of tests of circumferentially notched tensile(CNT)bars,the calibration procedure automatically determines the parameters of the strain hardening law as well as the uncoupled models and the coupled GTN constitutive model.Validation studies show accurate prediction of the load-displacement response and ductile fracture initiation in V-notch specimens,and confirm the PSO algorithm as an effective and robust algorithm for seeking ductile fracture model parameters.PSO has excellent potential for identifying other fracture models(e.g.,shear modified GTN)with many parameters that can give rise to more accurate predictions of ductile fracture.Limitations of the PSO algorithm and the current calibrated ductile fracture models are also discussed in this paper. 展开更多
关键词 Parameter calibration Void growth model(VGM) Gurson-Tvergaard-Needleman(GTN)model A36 steel A572 Gr.50 steel A992 steel Particle swarm optimization(PSO)
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Calibration of discrete element simulation parameters and threshing test for complete wheat plants 认领 引用 被引量：2
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作者 Shengsheng Wang Weizhen Lyu +3 位作者 Xin Jin Shuo Yu Hao Guo Zhonghan Chen 《International Journal of Agricultural and Biological Engineering》 SCIE 2025年第3期12-18,共7页
The existing discrete element model of wheat plants lacks the glume,which hinders the simulation of the entire threshing process.To address this issue,this paper takes wheat at the harvest stage as the research object... The existing discrete element model of wheat plants lacks the glume,which hinders the simulation of the entire threshing process.To address this issue,this paper takes wheat at the harvest stage as the research object and constructs a complete discrete element model of wheat plants with glumes based on the Hertz-Mindlin with bonding model in the EDEM simulation software.The parameter calibration of wheat glumes discrete element model is studied through collision bounce experiments,slope experiments,and accumulation experiments.The results show that the coefficient of restitution,coefficient of static friction,and coefficient of rolling friction between glume and steel are 0.488,0.625,and 0.048,respectively,and the coefficient of restitution,coefficient of static friction,and coefficient of rolling friction between glume and glume are 0.232,0.966,and 0.059,respectively.The relative errors between the simulation results and the measured values are less than 5%,and the calibration parameters are effective.Based on the structural parameters of the self-developed experiment-bed of tangential axial-flow grain threshing device,a three-dimensional model of the wheat threshing device is established to simulate the whole threshing process of the complete wheat plant,and the bench-scale experiments are carried out with the non-threshing rate as the performance index.The results indicate that the model can completely simulate the separation process of glume and grain and the movement law of different grains,and the relative error of non-threshing rate between the simulation experiments and bench-scale experiments is 4.36%.This further demonstrates that the proposed model can provide a reference for the wheat threshing process research and device performance optimization design. 展开更多
关键词 discrete element method wheat plant glume model parameter calibration threshing experiments
Triaxial elastoplastic damage constitutive model of unreinforced clay brick masonry wall 认领 引用 被引量：2
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作者 Wu Biye Dai Junwu +1 位作者 Bai Wen Yang Yongqiang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第1期157-172,共16页
Due to differences in the properties of composition materials and construction techniques,unreinforced masonry is characterized by low strength,anisotropy,nonuniformity,and low ductility.In order to accurately simulat... Due to differences in the properties of composition materials and construction techniques,unreinforced masonry is characterized by low strength,anisotropy,nonuniformity,and low ductility.In order to accurately simulate the mechanical behavior of unreinforced brick masonry walls under static and dynamic loads,a new elastoplastic damage constitutive model was proposed and the corresponding subroutine was developed based on the concrete material constitutive model.In the proposed constitutive model,the Rankine strength theory and the Drucker-Prager strength theory were used to define the tensile and compressive yield surface function of materials,respectively.Moreover,the stress updating algorithm was modified to consider the tensile plastic permanent deformation of masonry materials.To verify the accuracy of the proposed constitutive model,numerical simulations of the brick masonry under monotonic and cyclic uniaxial tension and compression loads were carried out.Comparisons among the numerical and theoretical and experimental results show that the proposed model can properly reflect the masonry material mechanical properties.Furthermore,the numerical models of four pieces of masonry walls with different mortar strengths were established.Low cyclic loadings were applied and the results show that the proposed constitutive model can properly simulate the wall shear failure characteristics,and the force-displacement hysteretic curves obtained by numerical simulation are in good agreement with the tests.Overall,the proposed elastic-plastic damage constitutive model can simulate the nonlinear behavior of unreinforced brick masonry walls very well,and can be used to predict the structural response of masonry walls. 展开更多
关键词 brick masonry elastoplastic model calibration parameters numerical simulation damage variable
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DEM parameter calibration approach for cohesive ores based on PSO-BP neural network 认领 引用
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作者 Fangping Ye Yanan Zhang +3 位作者 Craig Wheeler Bin Chen Chao Zhou Lei Nie 《Particuology》 SCIE EI CAS CSCD 2026年第8期309-320,共12页
To enhance the calibration efficiency and accuracy of Discrete Element Method(DEM)parameters for cohesive bulk materials,a collaborative method integrating Particle Swarm Optimization(PSO)and Backpropagation(BP)neural... To enhance the calibration efficiency and accuracy of Discrete Element Method(DEM)parameters for cohesive bulk materials,a collaborative method integrating Particle Swarm Optimization(PSO)and Backpropagation(BP)neural networks is proposed.Key macroscopic indicators(steady-state shear stress,angle of repose)are obtained via Jenike shear and funnel tests across a 0-50%moisture range.Orthogonal experiments determine micro-parameters(e.g.,staticolling friction,surface energy)to build a macro-micro mapping database.The core of the PSO-BP dual-model lies in its collaborative mechanism:the forward BP model predicts macroscopic responses to replace time-consuming DEM simulations,while the PSO algorithm optimizes the inverse BP model to accurately infer optimal micro-parameters from experimental macro-indicators(steady-state shear stress,angle of repose).Validation shows low errors(1.14%for angle of repose,1.63%for steady-state shear stress)and good chute flow velocity agreement.This method overcomes traditional limitations of arbitrariness and ignored parameter coupling,providing reliable support for DEM simulation and equipment design for cohesive bulk materials. 展开更多
关键词 Cohesive ores DEM parameter calibration PSO-BP neural network Angle of repose Shear test
Calibration and experimental verification of discrete element parameters of Panax notoginseng root 认领 引用 被引量：6
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作者 Kaiting Xie Zhaoguo Zhang +3 位作者 Fa’an Wang Xiaolan Yu Chenglin Wang Shifei Jiang 《International Journal of Agricultural and Biological Engineering》 SCIE 2024年第4期13-23,共11页
Existing discrete element method-based simulation analysis of Panax notoginseng root soil separation still has the challenge to get the accurate and reliable basic parameters,which are necessary for discrete element s... Existing discrete element method-based simulation analysis of Panax notoginseng root soil separation still has the challenge to get the accurate and reliable basic parameters,which are necessary for discrete element simulation.In this paper,the P.notoginseng roots suitable for harvesting period were taken as the experimental object.Then using 3D scanning reverse modeling technology and EDEM software to establish the discrete element model of P.notoginseng,based on which,the physical and virtual tests were carried out to calibrate the simulation parameters.First,the basic physical parameters(density,triaxial geometric size,moisture content,shear modulus,and elastic modulus)and contact coefficients(static friction coefficient,rolling friction coefficient,and crash recovery coefficient between P.notoginseng roots and 65Mn steel)were measured by physical tests.Furthermore,treating the contact coefficients of P.notoginseng roots as the influence factor,the steepest uphill test,and four factors combing five levels of rotational virtual simulation are conducted.The measured relative error accumulation angle and simulation accumulation angle are set as the performance indices.The results show that the static friction coefficient,rolling friction coefficient,crash recovery coefficient,and surface energy coefficient of P.notoginseng roots are 0.55,0.35,0.16,and 19.5 J/m2,respectively.Using calibration results as parameters of the vibration separation simulation test of P.notoginseng soil,the Box-Behnken vibration separation simulation tests were carried out,in which the vibration frequency,inclination angle,and vibration amplitude of separation device as factors,screening rate and damage rate of P.notoginseng soil complex are regarded as indices.The results show that the optimal operating parameters of the separation device are the vibration frequency of 10 Hz,the inclination angle of 5°,and the amplitude of 6 cm.Based on the optimal operation parameters,the discrete element simulation experiment and field experiment of P.notoginseng roots soil separation are also performed to compare the soil three-dimensional trajectory space coordinates of P.notoginseng roots.From the results,three axis coordinate error is less than 15%.This proves that the calibration results are reliable.It can also provide the theoretical basis and technical support for the further study of the P.notoginseng root soil separation platform. 展开更多
关键词 Panax notoginseng root EDEM parameter calibration separation test
Discussion of Muskingum method parameter X 认领 引用 被引量：4
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作者 Rui Xiaofang Liu Fanggui Yu Mei 《Water Science and Engineering》 CAS 2008年第3期16-23,共8页
The parameter X of the Muskingum method is a physical parameter that reflects the flood peak attenuation and hydrograph shape flattening of a diffusion wave in motion. In this paper, the historic process that hydrolog... The parameter X of the Muskingum method is a physical parameter that reflects the flood peak attenuation and hydrograph shape flattening of a diffusion wave in motion. In this paper, the historic process that hydrologists have undergone to find a physical explanation of this parameter is briefly discussed. Based on the fact that the Muskingum method is the second-order accuracy difference solution to the diffusion wave equation, its numerical stability condition is analyzed, and a conclusion is drawn： X ≤ 0.5 is the uniform condition satisfying the demands for its physical meaning and numerical stability. It is also pointed out that the methods that regard the sum of squares of differences between the calculated and observed discharges or stages as the objective function and the routing coefficients C0, C1 and C2 of the Muskingum method as the optimization parameters cannot guarantee the physical meaning of X. 展开更多
关键词 Muskingum method parameter X physical meaning numerical analysis stability condition parameter calibration
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